Ratanakosindra 1935
Ratanakosindra 1960
| Name | No | Yard No | Builder | Laid down | Launched | Comp | Fate |
| รัตนโกสินทร์ [Ratanakosindra] | Armstrong, Elswick, UK | 9.1924 | 21.4.1925 | 8.1925 | stricken 10.1967 | ||
| สุโขทัย [Sukothai] | Vickers-Armstrong, Barrow, UK | 12.1928 | 19.11.1929 | 12.1930 | stricken 1971 |
|
Displacement standard, t |
886 |
|
Displacement full, t |
1000 |
|
Length, m |
48.8 pp 53.0 oa |
|
Breadth, m |
11.3 |
|
Draught, m |
3.28 |
|
No of shafts |
2 |
|
Machinery |
2 VTE, 2 Yarrow boilers |
|
Power, h. p. |
850 |
|
Max speed, kts |
12 |
|
Fuel, t |
oil 96 |
|
Endurance, nm(kts) |
2000(10) |
| Armour, mm | belt: 57 - 32, deck: (25 - 13) + 25, turrets: 38, barbettes: 38, CT: 120 |
|
Armament |
2 x 1 - 152/50 EOC TT, 4 x 1 - 76/40 EOC N |
|
Complement |
102 |
Project history: Program of
strengthening of Siamese Navy accepted in 1914 provided the order in the Great Britain
of two original armoured gunboats (actually low-freeboard monitors). Total displacement should make 1070t, armament
consisted from 4 152mm/50 and 4 76mm/40 Armstrong guns, machinery included VTEs and cylindrical
coal-firing boilers. Lead Ratanakosindra was laid down in 1914 by
Armstrong in Elswick, but in connection with beginning of the First World War
building was suspended, and partially assembled hull was broken up to clear a slipway.
Ship was re-ordered in 1924 under changed design. Number of main guns was
decreased to two, cylindrical boilers were replaced by Yarrow oil-firing water-tube
boilers, also VTEs of a new construction were
installed, but with the same power. The given measures have allowed to increase a fuel stowage (normal
from 15 to 85t, and full from 50 to 96t) and thus to decrease a draught a little.
Ratanakosindra was built at High Walker, 10.8.1925 she was commissioned and 31.8.1925
departured from Britain to Siam, but those day she received damages as result of collision and returned
to builder for repair; she ultimately left Great Britain 29.10.1925. Sukothai ("City of angels": a poetical
name of Bangkok) was ordered in 1928 to already Vickers-Armstrong, building was conducted in Barrow.
Ships differed by rather unusual hull structure combining low free board typical for monitors with
raised forecastle, improving seaworthiness. On trials Ratanakosindra shown 12.892kts. Outwardly Sukothai differed
by increased bridge and transferred on 3m aftward funnel.
Ship protection: Main belt, 2m in height, had 57mm thickness amidships, decreasing to 32mm at ship ends. There were two armoured decks: upper had 25mm thickness over machinery, 19mm over aft end and 13mm over fore end, lower deck was uniform with 25mm thickness. Turrets and barbettes had 38mm protection from all directions, CT had 120mm armour.
Modernizations: mid-1930s, both: + 2 x 1 - 40/39 2pdr QF Mk II
mid-1940s, both: + 2 x 1 - 20/65 Breda 1939
1960s, both (presumably): + radar
Naval service: Both ships served more than 40 years.
Ratanakosindra 1926
Ratanakosindra 1950
© Ivan Gogin, 2011-15